challange-496.js

// problem
// The next greater element of some element x in an array is the first greater element that is to the right of x in the same array.
// You are given two distinct 0-indexed integer arrays nums1 and nums2, where nums1 is a subset of nums2.
// For each 0 <= i < nums1.length, find the index j such that nums1[i] == nums2[j] and determine the next greater element of nums2[j] in nums2. If there is no next greater element, then the answer for this query is -1.
// Return an array ans of length nums1.length such that ans[i] is the next greater element as described above.

// Example 1:
// Input: nums1 = [4,1,2], nums2 = [1,3,4,2]
// Output: [-1,3,-1]
// Explanation: The next greater element for each value of nums1 is as follows:
// - 4 is underlined in nums2 = [1,3,4,2]. There is no next greater element, so the answer is -1.
// - 1 is underlined in nums2 = [1,3,4,2]. The next greater element is 3.
// - 2 is underlined in nums2 = [1,3,4,2]. There is no next greater element, so the answer is -1.

// solution
var nextGreaterElement = function(nums1, nums2) {
    let ans = []
    for(let i=0; i< nums1.length; i++){
        let counter = 1
        const iNum1OnNum2 = nums2.indexOf(nums1[i])
        if(nums2[iNum1OnNum2+1] > nums2[iNum1OnNum2]){
            ans.push(nums2[iNum1OnNum2+1])
        } else if(iNum1OnNum2 < nums2.length-2) {
            while(nums2[iNum1OnNum2+1+counter] <nums2[iNum1OnNum2]){
                counter ++
            }
            if(nums2[iNum1OnNum2+1+counter]){
                ans.push(nums2[iNum1OnNum2+1+counter])
            } else ans.push(-1)
        } else {
            ans.push(-1)
        }
    }
    return ans
};